<?php
namespace wechat;
class jssdk{
    private $appId;
    private $appSecret;
    private $url;

    public function __construct($appId, $appSecret,$url) {
        $this->appId = $appId;
        $this->appSecret = $appSecret;
        $this->url = $url;

    }

    public function getSignPackage() {
        $jsapiTicket = $this->getJsApiTicket();

        // 注意 URL 一定要动态获取，不能 hardcode.


        $timestamp = time();
        $nonceStr = $this->createNonceStr();

        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=".$this->url;

        $signature = sha1($string);

        $signPackage = array(
            "appId"     => $this->appId,
            "nonceStr"  => $nonceStr,
            "timestamp" => $timestamp,
            "url"       =>  $this->url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }

    private function createNonceStr($length = 16) {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    private function getJsApiTicket() {
        // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
        $data = json_decode($this->get_php_file(root_path().'jsapi_ticket.txt'));
        if ($data->expire_time < time()) {
            $accessToken = $this->getAccessToken();
            // 如果是企业号用以下 URL 获取 ticket
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
            $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
            $res = json_decode($this->httpGet($url));
            $ticket = $res->ticket;
            if ($ticket) {
                $data->expire_time = time() + 7000;
                $data->jsapi_ticket = $ticket;
                $this->set_php_file(root_path().'jsapi_ticket.txt', json_encode($data));
            }
        } else {
            $ticket = $data->jsapi_ticket;
        }

        return $ticket;
    }

    private function getAccessToken() {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        $data = json_decode($this->get_php_file(root_path().'access_token.txt'));
        if ($data->expire_time < time()) {
            // 如果是企业号用以下URL获取access_token
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
            $res = json_decode($this->httpGet($url));

            //   var_dump($url);
            //   exit;
            $access_token = $res->access_token;
            if ($access_token) {
                $data->expire_time = time() + 7000;
                $data->access_token = $access_token;
                $this->set_php_file(root_path().'/access_token.txt', json_encode($data));
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }

//   private function httpGet($url) {
//     $curl = curl_init();
//     curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
//     curl_setopt($curl, CURLOPT_TIMEOUT, 500);
//     // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
//     // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
//     curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
//     curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, true);
//     curl_setopt($curl, CURLOPT_URL, $url);

//     $res = curl_exec($curl);
//     curl_close($curl);

//     return $res;
//   }
    public   function httpGet($url) {
        //设置附加HTTP头
        $addHead = array(
            "Content-type: application/json"
        );

        //初始化curl，当然，你也可以用fsockopen代替
        $curl_obj = curl_init();

        //设置网址
        curl_setopt($curl_obj, CURLOPT_URL, $url);

        //附加Head内容
        curl_setopt($curl_obj, CURLOPT_HTTPHEADER, $addHead);

        //是否输出返回头信息
        curl_setopt($curl_obj, CURLOPT_HEADER, 0);

        //将curl_exec的结果返回
        curl_setopt($curl_obj, CURLOPT_RETURNTRANSFER, 1);

        //设置超时时间
        curl_setopt($curl_obj, CURLOPT_TIMEOUT, 15);

        //执行
        $result = curl_exec($curl_obj);

        //关闭curl回话
        curl_close($curl_obj);

        return $result;
    }
    private function get_php_file($filename) {
        return trim(substr(file_get_contents($filename), 15));
    }
    private function set_php_file($filename, $content) {
        $fp = fopen($filename, "w");
        fwrite($fp, "<?php exit();?>" . $content);
        fclose($fp);
    }
}

